An assay developed by Axis-Shield (Dundee, Scotland) used to aid in the diagnosis of rheumatoid arthritis (RA) will soon be available for use with Abbott's (Abbott Park, Illinois) Architect immunoassay analyzer. The FDA has granted 510(k) clearance for the antibody cyclic-citrullinated peptide (anti-CCP) assay to run on the Abbott systems.

Because so many patients with RA develop an immune response against proteins containing citrulline long before they present symptoms of the disease, detecting the level of these antibodies earlier in the disease continuum, in conjunction with other clinical information, is critical to early diagnosis. The new test will be used by physicians if a patient is suspected of having RA or will be used to assist in the diagnosis or confirmation of a diagnosis of RA to measure anti-CCP concentrations in patients.

"The Anti-CCP assay is a completely different (from the current standard antinuclear antibody test) and it's fully automated test to provide physicians with additional information to assist in the diagnosis of patients who present symptoms of RA," Darcy Ross, senior manager, Abbott Diagnostics Division, public affairs, told Medical Device Daily. "A good disease marker should be sensitive and highly specific for the disease, detectable very early in the disease and useful for predicting outcomes. Studies indicate Anti-CCP satisfies all of these requirements."

It may be more accurate than current RA testing methods too.

In the early stages of RA, only one in five people test positive for RA and 15% to 20% of people with RA never test positive. In data provided by Abbott, clinical sensitivity was determined for 496 confirmed RA individuals, and clinical specificity was determined for 499 non-RA specimens. The sensitivity was calculated to be 70.6% with a specificity of 98.2%.

The American College of Rheumatology (Atlanta) treatment guidelines for RA recommends early diagnosis of the disease and timely introduction of therapies to prevent potentially irreversible joint damage. RA is a chronic autoimmune disease characterized by inflammation of the lining of the joints, which causes pain and disability. It afflicts about one in every 100 people.

"Anti-CCP is the name given to a family of autoantibodies directed against citrulline-containing proteins," Ross said. "The ARCHITECT assay is a chemiluminescent micro-particle immunoassay test that detects autoantibodies against second generation cyclic citrullinated peptides in human serum or plasma (CCP2)."

The assay was developed by Axis-Shield to run on Abbott's Architect i1000SR and i2000SR systems. Ross declined to reveal details of Abbott's deal with Axis-Shield.

"We are pleased to have received FDA clearance for this proprietary assay for RA on a major laboratory system," Ian Gilham, Axis-Shield CEO, said. "We believe this will help to address the growing demand for the anti-CCP test in the important American market and allow larger volume batch testing. RA is a potentially debilitating disease and early disease diagnosis facilitates improved treatment options and offers substantial patient benefits."

The anti-CCP assay is already approved and available on the Abbott Architect outside the U.S.

"The approval of the anti-CCP assay for use on the Architect provides an important tool for physicians to aid in the early diagnosis of RA. We are pleased to add this assay to the existing panel of autoimmune disease biomarker assays currently available on the Architect and clinical chemistry platforms as we underscore Abbott's continued commitment to the area of immunology," said Michael Warmuth, senior vice president, diagnostics, Abbott.

The assay is a chemiluminescent microparticle immunoassay (CMIA) for the semi-quantitative determination of the lgG class of autoantibodies specific to CCP in human serum or plasma.

Abbott's Architect analyzers include a robotic sample handler to prioritize emergency tests, sample clot and bubble detection to verify sampling integrity and FlexRate and Chemflex assay technologies.

Ross said the company expects to launch the new RA test in the U.S. within the next few weeks. n

Lynn Yoffee, 770-361-4789;